#include <stdio.h>
#include <math.h>

int main()
{
	int a,b,c;
	float area,s,perimeter;
	scanf("%d %d %d",&a,&b,&c);
	if(a+b>c&&a+c>b&&b+c>a){
		s=(a+b+c)/2.0;
		area=sqrt(s*(s-a)*(s-b)*(s-c));
		perimeter=a+b+c;
		printf("area = %.2f; perimeter = %.2f",area,perimeter);
		
	}else{
		printf("These sides do not correspond to a valid triangle");
	}return 0;
}
